What this means for learners
Slovene and Catalan share 26 sounds — roughly 67% of Catalan's inventory overlaps with Slovene. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 13 sounds found only in Catalan represent the greatest pronunciation challenge for Slovene speakers. The adult brain tends to map unfamiliar sounds onto the closest native equivalent — a process that produces the characteristic "accent" of a second-language speaker. Learning to hear and produce these sounds as distinct requires focused ear training, not just repetition.
Conversely, Slovene has 11 sounds not used in Catalan. Native Catalan speakers learning Slovene will face the mirror-image challenge with these sounds.
Phoneme inventories from PHOIBLE. Data reflects one documented inventory per language; some variation exists across dialects and sources.